The present invention relates to a spherical, hydrophilic silica, the method of its preparation as well as its use.
It is known that silicon tetrachloride and water can be preheated separately to 600.degree. C. and reacted with one another at this temperature over a period of 12 hours. The result is a wettable silica powder with an average particle size of 0.3 .mu.. The same publication also teaches that water vapor and silicon tetrachloride can be reacted with one another for 5 hours at a temperature of 300.degree. C. This yields a silica powder with an average particle size of 0.2 .mu.m (see DE-A No. D 13 400 IVa/12 of Dec. 29, 1955).
However, the silica powder prepared according to the state of the art has the disadvantage that it is too fine for the intended usage.